This disclosure relates to a fluid machine such as a liquid pump, a vacuum pump, a compressor, a blower, or an expander.
A vane pump has, for example a rotor, a cam ring, a vane, a supply port and an outlet port. The vane goes in and out a plurality of vane grooves radially formed in a rotor such that the vane has slide contact with the inner circumferential surface of the cam ring in response to the rotation of the rotor. The supply port supplies fluid to the pump space between the cam ring and the rotor and the outlet port permits the egress of the fluid. Such a vane pump becomes large in size because the vane pump is attached to a motor. Japanese Unexamined Patent Application Publication No. JP, 2011-117391, A (Jun. 16, 2011) discloses a small size vane pump. A stator is in a motor housing. A motor rotor is in the stator. A shaft rotates integrally with the motor rotor. A nonmagnetic pump rotor rotates integrally with the shaft and has a plurality of vane grooves on the circumferential surface thereof. A soft magnetic cam ring has an inner circumferential surface for accommodating the pump rotor. A soft magnetic vane is slidably accommodated in each vane groove so as to slide contact the inner circumferential surface of the cam ring. A soft magnetic pump housing accommodates the cam ring. The inner circumferential surface of the pump housing has contact with the outer circumferential surface of the cam ring. A part of the pump housing has contact with the stator. The volume of a plurality of pump chambers surrounded by the outer circumferential surface of the pump rotor, the inner circumferential surface of the cam ring and the vane is changed in accordance with the rotation of the pump rotor. The vane pump pulls the vane in accordance with magnetic action in a direction such that the vane gets out of the vane groove of the rotor. Although the size of the vane pump is reduced without a spring, the size cannot be sufficiently small because the pump section is configured separately from the motor section.